Microwave Drying Characteristics and Antidiabetic Properties of Aquilaria subintegra and Aquilaria malaccensis Leaves

2015 ◽  
Vol 1113 ◽  
pp. 352-357 ◽  
Author(s):  
Sxureha Yunus ◽  
Nurul Asyikin Md Zaki ◽  
Ku Halim Ku Hamid
Keyword(s):  
Power Level ◽  
Microwave Treatment ◽  
Microwave Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Aquilaria Malaccensis ◽  
Treatment Of Diabetes ◽  
Drying Curves ◽  
Vitro Analysis

The present study was aimed to investigate the effect of microwave drying on the anti-diabetic potential of the leaves of Aquilaria subintegra and Aquilaria malaccensis with regard to its efficacy by local herbalists in the treatment of diabetes frailties. The drying process was carried out at 50, 100 and 150 W, and the drying curves were developed to analyse the drying characteristics of both species of Aquilaria leaves. Solid-liquid extraction was done by using ethanol as solvent prior to in-vitro analysis of the inhibition activity on α-amylase. Following that, HPLC and FTIR were done to support findings on the antidiabetic compounds of the leaves extract. The results indicated that an increase in power level will reduce the drying time during microwave treatment. Findings showed that both species of Aquilaria leaves extract could remarkably inhibit the activity of α-amylase and provide a rationale for the use of the leaves in the treatment of diabetes mellitus.

Study of color kinetics of banana (Musa cavendish) under microwave drying by application of image analysis

2020 ◽  
pp. 108201322098133
Author(s):  
Sagar Nagvanshi ◽  
Subbarao Kotra Venkata ◽  
TK Goswami
Keyword(s):  
Microwave Power ◽  
Vision System ◽  
Power Level ◽  
Microwave Drying ◽  
Slice Thickness ◽  
Order Kinetic ◽  
Drying Time ◽  
Volumetric Heating ◽  
Kinetics Of ◽  
Microwave Power Level

Microwave drying works on the volumetric heating concept promoted by electromagnetic radiation at 0.915 or 2.450 GHz. In this study, banana ( Musa Cavendish) was taken as the sample and treated under microwave drying. The effect of two process variables, namely slice thickness (2, 3.5, and 5 mm) and microwave power (180 W, 360 W, and 540 W), were studied on drying kinetics and color kinetics. It was observed that the inverse variation relationship exists between drying time and microwave power level while drying time and slice thickness exhibited a direct variation relationship. A Computer Vision System (CVS) was developed to measure the color values of banana in CIELab space using an algorithm written in MATLAB software. Once the color parameters were obtained, they were fitted in First and Zero-order kinetic models. Both models were found to describe the color values adequately. This study concludes that microwave drying is a promising dehydration technique for banana drying that reduces the significant time of drying. Application of CVS is an excellent approach to measure the surface color of banana.

The thin-layer drying characteristics of sewage sludge by the appropriate foaming pretreatment

2014 ◽  
Vol 69 (9) ◽  
pp. 1859-1866 ◽  
Author(s):  
Hui-Ling Wang ◽  
Zhao-Hui Yang ◽  
Jing Huang ◽  
Li-Ke Wang ◽  
Cheng-Liu Gou ◽  
...  
Keyword(s):  
Sample Thickness ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying ◽  
Dewatered Sludge ◽  
Drying Curves ◽  
Sludge Drying ◽  
The Impact

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature, which could save 35–45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm3 was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.

Influence of Different Drying Methods on Drying Characteristics, Carotenoids, Chemical and Physical Properties of Gac Fruit Pulp (Momordica cochinchinensis L.)

2016 ◽  
Vol 12 (4) ◽  
pp. 395-409 ◽  
Author(s):  
Wittawat Trirattanapikul ◽  
Singhanat Phoungchandang
Keyword(s):  
Antioxidant Activity ◽  
Heat Pump ◽  
Total Phenolics ◽  
Microwave Drying ◽  
Drying Methods ◽  
Fruit Pulp ◽  
Model Quality ◽  
Drying Time ◽  
Drying Characteristics ◽  
Momordica Cochinchinensis

Abstract Gac fruit (Momordica cochinchinensis L.) pulp is high in carotenoids and fiber; however, it is discarded during process. Both maturity stages of matured gac fruit could be used in the drying experiments. Gac fruit pulp was dried by different drying methods including tray drying (40–60 °C), heat pump-assisted dehumidified drying (40–60 °C), microwave drying (450–900 W), mixed-mode solar drying and freeze drying. The Modified Henderson model presented the best fit of desorption isotherms. New model proposed was the best drying model. Quality evaluation by β-carotene, lycopene, lutein, total phenolics and antioxidant activity revealed that heat pump-assisted dehumidified drying at 60 °C provided the highest lutein, total phenolics and antioxidant activity and could reduce drying time by 25 % and increased lutein, total phenolics and antioxidant activity by 12.6 %, 32.0 % and 0.3 %, respectively and is more promising drying method for gac fruit pulp.

Convective and microwave drying characteristics, energy requirement and color retention of dehydrated nettle leaves (Urtica diocia L.)

2017 ◽  
Author(s):  
Fuat Lule ◽  
Turhan Koyuncu
Keyword(s):  
Moisture Content ◽  
Air Temperature ◽  
Energy Requirement ◽  
Color Difference ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Color Retention ◽  
Specific Energy Requirement

In this research, convective and microwave drying characteristics, energy requirement and color changes of nettle leaves (Urtica diocia L.) were reported. Samples of freshly harvested nettle leaves were dehydrated under three air temperatures of 50 °C, 60 °C and 70 °C and at three microwave power levels of PL-1, PL-2 and PL-3. Selected drying air velocity was 0.30 m/s for all temperatures. This is coming from the fact that it was understood from the preliminary studies that the temperature less than 50 °C and the air speed more than 0.30 ms-1 increase the drying time and energy requirement, extremely for these products. Nettle leaves were dehydrated from the initial moisture content of 320 (percentage dry basis) to a final moisture content of 7 % to 9 %. During convective drying experiments, product were weighted automatically by the balance per (5 to10) min. Data were transferred to the computer and processed by a software. During microwave drying, the product were weighted and data recorded manually per (15 to 60) min. The influence of drying method, drying air temperature and microwave power level have also been studied. Hunter L, a, b values system was also used to evaluate changes in total color difference (DE) on dried products. The results showed that convective drying air temperature and microwave oven power levels influenced the total drying time, total energy requirement, specific energy requirement and color difference for nettle leaves. The minimum specific energy requirement were determined as 6.95 kWhkg-1 and 23.63 kWhkg-1 for 70 °C and PL-2 respectively. 70 °C drying air temperature and PL-3 was found to yield better quality product in terms of color retention of Hunter L, a, b and DE. As a result, to reduce drying energy consumption and to keep better color retention, convective drying can be recommended for this application.

Experimental Study on the Xilingol Lignite Dewatering in Microwave Field

2013 ◽  
Vol 868 ◽  
pp. 442-446
Author(s):  
Wei Dong Wang ◽  
Xiao Yang ◽  
Jing Wen ◽  
Meng Hui Lu ◽  
Chen Gao ◽  
...  
Keyword(s):  
Microwave Field ◽  
Size Composition ◽  
Microwave Drying ◽  
Drying Rate ◽  
Drying Characteristics ◽  
Fine Coal ◽  
Mass Losses ◽  
Drying Rates ◽  
Drying Curves ◽  
Superficial Area

Microwave drying characteristics of Xilingol lignite were investigated with microwave drying testing equipment at 2450 MHz. Effects of particle size has been carefully studied. Mass losses of the samples were measured during drying. Drying rates were then obtained through the trends of drying curves. Results show the 0.6-1mm sample has low drying rate. Changing the stacking superficial area and size composition has been tested and resulted that only mixed with fine coal can increase the drying rate of 0.6-1mm. But classification experiment shows sieving 0-6mm sample into fine sample and coarse sample cannot advance the drying rate obviously.

scholarly journals Pulsed air jet impingement drying characteristics of winter jujube slices

2018 ◽  
Vol 36 (No. 4) ◽  
pp. 324-332
Author(s):  
Wei Shi-Yu ◽  
Wang Gao ◽  
Huang Yong ◽  
Zhu Rong-Guang ◽  
Wang Qiang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Effective Diffusivity ◽  
Jet Impingement ◽  
Statistical Parameters ◽  
Drying Time ◽  
Drying Characteristics ◽  
Wind Speeds ◽  
Air Jet ◽  
Drying Curves ◽  
Moisture Effective Diffusivity

The drying curves, moisture effective diffusivity and drying activation energy of winter jujube slices were here investigated at different drying temperatures (55, 60, 65, 70, 75, and 80°C), wind speeds (6, 7, 8, 9, and 10 m/s) and pulsation rates (rotatational speed of material disk: 4, 5.5, and 7 rpm) in a single-factor experiment design. A mathematical model of pulsed air-jet impingement drying for winter jujube slices was fitted and verified. The results showed that the entire drying process could be described as falling rate drying; the moisture effective diffusivity was in the range 1.52–4.93 × 10<sup>–9</sup> m<sup>2</sup>/s and increased with increasing drying temperature, wind speed and pulsation rate. The drying activation energy was 43.9 kJ/mol as determined using the Arrhenius equation. According to the statistical parameters of the correlation coefficient (R<sup>2</sup>), root mean square error (RMSE) and the sum of squared errors (SSE), the modified Page model was selected as best for representing the correlation between moisture ratio and drying time.

scholarly journals Modelling the Drying Characteristics and Kinetics of Hot Air-Drying of Unblanched Whole Red Pepper and Blanched Bitter Leaf Slices

2017 ◽  
Vol 5 (1) ◽  
pp. 24
Author(s):  
Samuel Enahoro Agarry
Keyword(s):  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Red Pepper ◽  
Coefficient Of Determination ◽  
Drying Time ◽  
Drying Characteristics ◽  
Hot Air ◽  
Effective Moisture ◽  
Drying Curves ◽  
Kinetics Of

The objective of this study was to investigate the drying characteristics and kinetics of red pepper and bitter leaf under the influence of different drying temperatures. The drying experiments were carried out at dry bulb temperature of 35, 45, 55 and 75oC, respectively in an oven dryer. The results showed that as drying temperature increased, drying rate also increased and the drying time decreased. It was observed that un-sliced red pepper and sliced bitter leaf would dry within 2.5-12 h and 1.67-7 h, respectively at temperature ranging from 75 to 35oC. The drying of red pepper and bitter leaf was both in the constant and falling rate period. Four semi-empirical mathematical drying models (Newton, Page, Henderson and Pabis, and Logarithmic models) were fitted to the experimental drying curves. The models were compared using the coefficient of determination (R^2) and the root mean square error (RMSE). The Page model has shown a better fit to the experimental drying data of red pepper and bitter leaf, respectively as relatively compared to other tested models. Moisture transport during drying was described by the application of Fick’s diffusion model and the effective moisture diffusivity was estimated. The value ranges from 15.69 to 84.79 × 10-9 m2/s and 0.294 to 1.263 × 10-9 m2/s for red pepper and bitter leaf, respectively. The Arrhenius-type relationship describes the temperature dependence of effective moisture diffusivity and was determined to be 37.11 kJ/mol and 32.86 kJ/mol for red pepper and bitter leaf, respectively. A correlation between the drying time and the heat transfer area was also developed.

scholarly journals Influence of intermittent and continuous microwave heating on drying kinetics and wood behavior of Eucalyptus Gomphocephala

2018 ◽  
Author(s):  
Mariam Habouria ◽  
Sahbi Ouertani ◽  
Soufien Azzouz ◽  
Wahbi Jomaa ◽  
Mohamed Taher Elaib ◽  
...  
Keyword(s):  
Power Level ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Continuous Heating ◽  
Average Moisture Content ◽  
Processing Parameter ◽  
Drying Time ◽  
Optimal Processing ◽  
Eucalyptus Wood ◽  
Eucalyptus Gomphocephala

 The aim of this work was to determine the microwave drying kinetics of Eucalyptus Gomphocephala wood  and to investigate the influence of intermittent and continuous heating  processes on the end quality of dreid samples.  The average moisture content evolution and temperature of wood samples under different microwave powers were analyzed in terms of drying time and internal temperature level. Results show that the increase of microwave power level decreses the drying time and increases the internal wood temperature. Based on qualitative observations on the state of dried samples, the intermittent microwave powers intensity process present the optimal processing parameter in microwave drying of  Eucalyptus wood species.Keywords: microwave drying; power; intermittent; continuous; Eucalyptus wood.  

scholarly journals Effect of Microwave Drying on the Drying Characteristics, Color, Microstructure, and Thermal Properties of Trabzon Persimmon

Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 84 ◽  
Author(s):  
Soner Çelen
Keyword(s):  
Energy Consumption ◽  
Color Change ◽  
Power Level ◽  
Effective Diffusion ◽  
Microwave Energy ◽  
Microwave Drying ◽  
Slice Thickness ◽  
Fresh Sample ◽  
Drying Time ◽  
Color Changes

In this study, changes in the drying kinetics, color change, and the energy consumption for microwave energy were investigated for Trabzon persimmon. In addition to that, the microstructure of the persimmon was also investigated by considering its thermal changes. It is important to be aware of the purpose of the drying process for determining the drying system. Results of this research showed that 460 W for 7 mm slice thickness depending on energy consumption, 600 W for 5 mm slice thickness depending on drying time, and 600 W depending on color changes were found as suitable drying processes depending on drying conditions. The effective diffusion values varied between 2.97 × 10−8 m2 s−1 and 4.63 × 10−6 m2 s−1. The activation energy values for 5 mm, 7 mm and 9 mm slice thickness were estimated as 32.82, 18.64, and 12.80 W g−1, respectively. The drying time and energy consumption decreased, whereas drying rate increased with an increase in the microwave energy. The number of pores increased compared to structure of fresh sample, and the pores got to be larger for 5 mm slice thickness as the power level increased. Results showed that the applied microwave energy had an important effect on the heating of the material and the change in the microstructure.

scholarly journals Vacuum-assisted microwave drying characteristics of green bell pepper

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Vivek Kumar ◽  
Shanker L. Shrivastava
Keyword(s):  
Moisture Diffusivity ◽  
Bell Pepper ◽  
Microwave Drying ◽  
Drying Methods ◽  
Drying Time ◽  
Drying Characteristics ◽  
Hot Air ◽  
Potassium Metabisulphite ◽  
Temperature Ranges ◽  
Air Dryer

Chopped green bell pepper pieces were blanched (95 °C, 5 min) and chemically pretreated (1% potassium metabisulphite solution, 25 min at room temperature) before drying in hot air dryer (HAD) at various temperature ranges (60 – 80 °C). Three vacuum levels (200, 400, 600 mm Hg) and microwave power levels (100, 200, 300 W) were also used to dry green bell pepper samples in a vacuum assisted microwave (VAM) (2.45 GHz, 0.8 kW) dryer. VAM drying methods offered a maximum reduction by four to five times in drying time as compared to that in HAD. The logarithmic model was found to have the best fit based on high R2 and small values of reduced χ2 and RMSE.  VAM method has higher values for effective moisture diffusivity (Deff) and lower values for activation energy (Ea), in comparison to the HAD method. 

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